Wednesday, June 06, 2007

I love the smell of if-then in the morning, it smells like … validity (mmm, pineapple)

This is a follow-up to last night’s post, which might be deemed a bit frivolous for the way it skidded over the only point that was actually, potentially, philosophically substantive (yes, even I make frivolous posts, even I, time to time.)

Why should the sort of thing Wittgenstein is wondering about (what makes me look up/down) be an interesting philosophical topic? I mentioned ‘secondary sense’, without really elucidating. Let’s start with Part II of Philosophical Investigations:

Given the two ideas ‘fat’ and ‘lean’, would you be rather inclined to say that Wednesday was fat and Tuesday lean, or vice versa. (I incline decisively toward the former.) Now have “fat” and “lean” some different meaning here from their usual one? - They have a different use. - So ought I really to have used different words? Certainly not that. - I want to use these words (with their familiar meanings) here. - Now, I say nothing about the causes of this phenomenon. They might be associations from my childhood. But that is a hypothesis. Whatever the explanation, - the inclination is there.

Asked “what do you really mean here by ‘fat’ and ‘lean’?” - I could only explain the meaning in the usual way. I could not point to the examples of Tuesday and Wednesday.

Here one might speak of a ‘primary’ and ‘secondary’ sense of a word. It is only if the word has the primary sense for you that you can use it in the secondary one. (p. 216)

So there you go: synaesthesia, plus connotation (maybe), plus cultural facts, plus who knows what else? There is quite a bit about this this stuff in the later Wittgenstein - aspect-dawning, the duck-rabbit, seeing-as.

“The aroma of coffee is indescribable”. No description? - But what would a description be like? “No words can give you the idea.” But how do we know you have understood? I could tell you.

[Peter] Geach: The blind man and “Red is the sound of a trumpet”.

Wittgenstein: I could explain the English word “red” to a foreigner by saying ‘sound of a trumpet’, or blowing a trumpet. Blindness is irrelevant.
Isadora Dunan Danced Schopenhauer.
Suppose a man recognized an aroma from my drawing? Have I then described the aroma? What is lacking? “It is in the wrong sphere”?

Geach: It might be different for different people.

Wittgenstein: If I say, “Bring me a flower nearer red than yellow”, isn’t that a different sphere.
But then ‘red’ and ‘yellow’ are learnt. (pp. 6-7)

My one original (so far as I know) textual connection to make here is to Russell’s (1903) Principles of Mathematics:

The discussion of indefinables - which forms the chief part of philosophical logic - is the endeavour to see clearly, and to make others see clearly, the entities concerned, in order that the mind may have that kind of acquaintance with them which it has with redness or the taste of a pineapple. (p. 6)

It is spectacularly unilluminating, to say the least, to say that (say) understanding the if-then relation is like the taste of pineapple (only about implication?)

At the start of Philosphical Investigations, Wittgenstein says he will sometimes imagine primitive language-games - and one main class of such cases will be hypothetical cases in which an actually wrong account of something would be right. If Russell were right about indefinables, then doing logic would always be a matter of being subject to some sort of bizarre synaesthetic experience. So talking about what synaesthesia is actually like can cure us of the empiricist delusion that this sort of ‘explanation’ is substantive. (Understanding ‘if-then’ is a matter of actually being able to go on in the same way, etc.)

But there is considerably more to it. It’s not as though Russell’s naive, circa-1903 version of empiricism still needed beating to death in 1946, although it is plausible that this sort of thing is always working in the back of Wittgenstein’s mind, given how much Russell influenced him. What is interesting to Wittgenstein is that ‘secondary sense’ isn’t exactly completely irrelevant, although clearly it’s more irrelevant than Russell thinks. But it’s hard say what role it can have. It seems as though if it could have a real, essential role, then private languages would be possible, for example.

Maybe I’ll say more later, but I’ll leave it at that for now. (Now you know what ‘secondary sense’ is, for Wittgenstein, maybe).

Comments

"If Russell were right about indefinables, then doing logic would always be a matter of being subject to some sort of bizarre synaesthetic experience.”

I don’t see how this follows. I took the point about the taste of pineappleto be Locke’s point: “No man can have the relish of a pine-apple until he goes to the Indies, where it is, and tastes it” (quote from memory). Similarly, no-one can grasp indefinables in logic except by direct acquaintance (whatever that would be). So, it would indeed be “spectacularly unilluminating… to say that (say) understanding the if-then relation is like the taste of pineapple”, but Russell’s not claiming that: he’s claiming that the means by which we come to understand the if-then relation is like the means by which we come to know what pineappletastes like - try it and see - and not (e.g.) like the means by which we come to know that the angles of a triangle add up to 180 degrees.

But what I’ve just written now looks so obvious that I think I must have misunderstood you. What have I missed?

Ben, if I can borrow a quote from one of my CT posts, couple weeks back, here’s the first paragraph of “Born on a Blue Day”, memoir of a synaesthetic savant, Daniel Dammet:

“I was born on January 31, 1979—a Wednesday. I know it was a Wednesday, because the date is blue in my mind and Wednesdays are always blue, like the number 9 or the sound of loud voices arguing. I like my birth date, because of the way I’m able to visualize most of the numbers in it as smooth and round shapes, similar to pebbles on a beach. That’s because they are prime numbers: 31, 19, 197, 79, and 1979 are all divisible only by themselves and 1. I can recognize every prime number up to 9,973 by their “pebble-like” quality. It’s just the way my brain works.”

Obviously Russell didn’t say that a sense for a logic relation is exactly like the taste of pineapple. The trouble is: anything that is close enough for that to be a good analogy is going to be too close to the Tammet case, which is surely not a paradigm of how we all do logic, in the ordinary course of things.

I still don’t see how Russell’s claim has anything to do with synesthesia. The synesthetic component of Tammet’s experience is that he automatically and consistently makes associations across sensory modalities: Wednesday is blue. Other synesthetics associate music with colour, for instance.

But Russell isn’t claiming that there’s any such cross-modality for logic relations. He’s claiming that we get a grip on two otherwise different kinds of thing (on the if-then relation, on the taste of pineapple) by the same empirical means: direct acquaintance. That sounds somewhat like the second part of Tammet’s experience, as described in your quote: he just sees the prime numberishness of 1979, where I’d have to work it out. But that’s not synesthesia (and is different from Russell’s indefinables in that there is a way for me to work it out).

Sorry to be a bit slow to respond. I’m laid low with nasty flu. First, I see your point. But I do think there’s something right about saying any experience of a logical relation would have to be cross-modal- because logical relations aren’t the sort of thing you can experience. You would have to be experiencing something whose RELATION to the logical relation was then quite problematic, i.e. apparently external but somehow experienced as internal. (Does that make sense?)

Tammet says he knows they are prime numbers by recognizing their pebble-like quality. That would be like saying: valid modus ponens-form inferences always taste of pineappleto me. So I am able to recognize them instantly. (Yes, it’s just an example. But, again, the sense of the logical relation has to be LIKE the taste of pineappleto some degree for the analogy to work at all.)

It seems to me that a correct objection to Russell is that, if what he said were correct, we would all think sort of like Tammet - i.e. synaesthetically - but we don’t seem to actually think that way.

John - thanks, that makes things much clearer, and I do now see your point. I’m not sure I buy it, though. Our related differences seem to be about:
1) whether one can experience logical relations; and
2) how literally to take Tammet’s description of prime numbers as ‘pebble-like’.

I’m tempted, on (2), to take Tammet’s claim as metaphorical: as saying that he just gets the prime-numberishness of 1979; that it feels like a prime number. The alternative literal reading would be that, when Tammet contemplates 1979, he gets cross-modal pebble-type sensations of hard, smooth, etc.

I admit I have no evidence for the metaphorical over the literal reading! But it perhaps illuminates what Russell is getting at. I actually do feel a certain amount of discomfort - a seeming wrong - about examples of denying the antecedent, for instance. And when I’ve been doing a fair amount of formal logic, I can sometimes just get how a proof is going to go (especially if it’s a reductio).

Where this is going is that (on 1) I think logical relations are the kind of thing one can experience, and experience in a very immediate, just getting it way. Teaching introductory formal logic (which I’ve been doing recently) is therefore importantly a matter of displaying basic forms of valid and invalid argument, in the hope that students will grasp them: that they’ll come to ‘have that kind of acquaintance with them which [they have] with redness or the taste of a pineapple’.